This is a hilariously out of touch move by Joyent.
The major concern most people have with node.js is the governance model - the fact that a single corporation controls it makes a lot of people uneasy.
This thin ploy really highlights exactly the kind of company that Joyent is and really validates those concerns. They're not interested in working together with io.js, they're interested in using their corporate muscle to squash what they see as a competitor.
The worst thing is the incentives they're using are barbed - really they're just offering you a discount on their products in return for locking you in to them.